1. Field of the Invention
The present invention relates to apparatus that control draft conditions in a fireplace and through a chimney flue, and particularly, to apparatus which are removably mountable to the chimney or a chimney cap.
2. Description of the Related Art
Damper apparatus are used with ventilation systems, fire box heating systems and chimney flues. Such apparatus usually require substantial effort to be installed and maintained for operation due to their complexity. In addition, these apparatus are not constructed to be removably mountable without altering the structure of the supporting object to which they are mounted.
For example, a ventilation system is disclosed in U.S. Pat. No. 2,171,883 to McDerment, where a rotary ventilator consisting of a fan and motor is supported within a roof coaming. A hood-like rotary cowl member is disposed over the fan and includes louvers arranged for pivotal movement. The louvers are connected to a lever which in turn is controlled by a cable member.
U.S. Pat. No. 2,564,971 to Harding, discloses means for reducing fire danger in hotels and consists of ports leading from a room to a duct formed by a false ceiling in the top of a hallway, each duct opening to a stack in which is disposed a power driven fan for cooling and ventilating. A curved baffle is provided where two aligned ports occur in opposed wall partitions to guide the draft from a room into the duct and to direct flame from a room into the duct toward the stack. The damper is automatically closed by a temperature sensitive link or a thermostatically expansible bellows.
U.S. Pat. No. 3,012,495 to Miller, discloses a combined air dampener and air diverter which consists of an inverted cone adapted to normally remain at rest atop an air stack where it is lifted to a raised position by the movement of air alone in the stack to a position abutting the underside of a dome which is spaced from the upper end of the stack. The conical shape is an air diverter when raised. A fan in the stack forces air upwardly through the stack which results in the inverted cone being moved to the raised position. When the fan ceases to rotate, the cone will rest as a damper and seal the upper end of the stack from the outside air.
U.S. Pat. No. 3,829,010 to Jones, discloses a thermostat for power ventilators which senses temperature level while a fan driven by an electric motor positioned in an opening of the roof blows air from the closed space to the exterior. When the closed space air temperature decreases to a certain level, the thermostat switches the power ventilator off in response to this temperature level.
U.S. Pat. No. 4,501,389 to Kolt, discloses an automatic damper assembly for ventilating systems and includes a conduit mounted to a roof with a wind driven turbine assembly or a fan mounted to an upper end of the conduit in which is disposed a pair of vanes. A motor is mounted to the top of the turbine. A temperature responsive drive assembly is disposed in the conduit to detect the conduit temperature and regulate opening and closing of the vanes in the air passageway of the conduit.
U.S. Pat. No. 5,123,875 to Eubank, et al., discloses a power actuated roof vent apparatus which consists of an air passageway housing through the roof of an enclosed area and a lid which closes the airflow therethrough. A power actuated fan assembly is positioned within the air passageway housing and is driven by a motor which can also be disposed within the air passageway housing. A switch controls the drive motor to open or close the passageway closure lid with the fan being actuated depending upon the position of the closure lid. A heat sensor and/or smoke detector may be incorporated within the switching system to close the lid during a fire.
Fireplace heating systems which employ damper elements are disclosed in the following patents.
U.S. Pat. No. 2,407,590 to Vineberg, discloses a heating apparatus which consists of a fire box, a flue connected thereto and a smoke condenser which interrupts the flue to permit an exchange of heat between the air and combustion products. The flue extends from the condenser to a fan which is driven by a motor for creating a forced draft from the firebox through the flue to discharge the smoke out-of-doors. Dampers are provided in the flue and may be electrically operated under the control of the speed of the fan motor. An electromagnetic device, such as a solenoid, is disposed at the fire box to automatically control a gate closing at the fire box to prevent smoke from entering the room. A fan draws air in at an inlet in front of the heater and beneath the fire box to pass cooling air over the motor.
U.S. Pat. No. 4,106,693 to Oliver, discloses an automatic fireplace heating system which consists of a fireplace, combustion zone, flue and damper for opening and closing the passageway from the combustion zone to the flue, the flue being divided into two parallel independent flue passages, one of which contains a heat exchanger adapted to absorb the heat from hot gases passing through the flue into air circulating inside the heat exchanger. A movable diverter directs the hot gases into either parallel flue or into both in desired proportions. A fan circulates the air from the heat exchanger. Thermostats sense the heat and the space to be heated to cause a solenoid to move the diverter to open or close the flue to any partial opening.
U.S. Pat. No. 4,143,817 to Oliver, discloses an automatic fireplace heating system which includes parallel flue passageways one of which is provided with a heat exchanger. A diverter is employed to divert flue gases into either or both the flue passages. A temperature sensing means is disposed in the heat exchanger flue passageway and a room thermostat temperature sensing means is also provided at an external room location.
Patents which disclose control mechanisms for fireplace dampers include U.S. Pat. No. 2,295,839 to Grigsby, where a chimney damper is installed at the top of the chimney. The damper consists of a shell open at its upper and lower ends and having a cross-shaft therein with its ends journaled in openings of opposed sidewalls of the shell. A damper plate is secured to the shaft to be moved between open and close positions by a chain connected thereto. The chain extends down the chimney to a weight which regulates the open and close position of the damper plate. A foraminous dome mounted to a flange at the outer end of the shell serves to break up sparks and prevent insects from entering the chimney.
U.S. Pat. No. 4,027,655 to Feldl, discloses a fireplace damper release mechanism which is adapted to automatically close the fireplace damper when the fire has gone out thereby avoiding loss of heat from the room to the fireplace chimney area. The mechanism includes a housing for receiving a vertical lower end portion of a fireplace damper connecting rod, which rod includes an upper end portion attached to the fireplace damper. The lower end portion of the rod rests in the housing to co-act with a pair of bimetallic/thermostatic metal strips which flex to regulate movement of the rod and therefore, the damper.
U.S. Pat. No. 4,235,219 to DeFoe, discloses an apparatus for damping fireplace flues which consists of a controller connected to a conventional damper by a suitable linkage. A temperature sensor element and latches co-act to actuate the linkage to open and close the damper.
U.S. Pat. No. 4,554,863 to Dalsin, discloses a chimney damper mounted to the top portion of the chimney flue and which includes a frame which extends above the flue opening and from which an extension spring depends to a flue cover to seal the top of the flue. The cover plate is connected to a stem which is operatively linked by a cable to a control device remotely mounted within the fireplace opening to pull the plate downwardly to cover the flue and to release the spring return to open the flue cover. The control device can be held at a select position depending upon the extent to which the damper is to be opened.
U.S. Pat. No. 4,649,808 to Ward, et al., discloses a fireplace damper assembly adapted to seal a vertical fireplace flue. The damper can be electrically actuated or automatically controlled by actuation of temperature and/or smoke detectors. A fan to provide for a draft and a wind protection hood for the top of the chimney are also disclosed. Thermocouples are installed in the firebox to sense fireplace temperature and in the control box to sense ambient temperature. A control automatically raises the external damper to permit the gases to be expelled through the flue. The damper is automatically closed when the temperature difference returns to low and/or the smoke diminishes. A motor is affixed to the roof and rotates a pulley to raise and lower a cable attached to the damper to be raised and lowered over the top of the flue.
U.S. Pat. No. 4,858,517 to Coker, discloses a fire damper kit for a flue which includes in combination a spring bias door maintained in a first opened position by means of a fusible link that is retracted to a closed second position upon destruction of the fusible link by fire within the damper duct work. A first collar is fixedly secured to the damper with a second collar slidable thereon to sandwich a firewall therebetween and secure the damper thereto.
None of the foregoing patents disclose a combination damper and chimney cap apparatus which is constructed to be removably mountable to a chimney or chimney cap to automatically regulate the draft between a fireplace and a chimney flue.
None of the foregoing patents disclose a combination damper and chimney cap apparatus which includes a support means specifically adapted to support all necessary elements to control the draft through the flue so that the apparatus can be removably mounted to a chimney or chimney cap as a single unit.